A press forming method forms a metal plate into the part shape having at least a top surface portion and side wall portions continuous with both left and right sides of the top surface portion, the part shape having a U-shaped or hat-shaped cross section and having one or two or more bent portions bent in a longitudinal direction that is a direction intersecting the cross section. The press forming method includes: a first step of applying in-plane shear deformation to a plate portion on both sides or one side of the bent portions in the longitudinal direction of the metal plate, the in-plane shear deformation corresponding to a direction of bending the portion of the part shape; and a second step of implementing press forming for the metal plate into the part shape, the metal plate to which the in-plane shear deformation has been applied.